Hi. I have a symptom that I can find here and there and the web, but I have never seen a solution. A seemingly random subsample of websites seem to be blocked on my computer, eg, www.wunderground.com. They would appear to consist of sites that I visit fairly often, though of course if sites I don't visit are blocked I wouldn't know about it. I have checked my HOSTS files and there is nothing there. Here is the log. I am running xp pro.

Logfile of HijackThis v1.99.1
Scan saved at 10:46:48 AM, on 8/7/2006
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)

Running processes:
C:\WINDOWS\System32\smss.exe
C:\WINDOWS\system32\winlogon.exe
C:\WINDOWS\system32\services.exe
C:\WINDOWS\system32\lsass.exe
C:\WINDOWS\system32\ibmpmsvc.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\System32\Ati2evxx.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgamsvr.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgupsvc.exe
C:\Program Files\Cisco Systems\VPN Client\cvpnd.exe
C:\WINDOWS\System32\QCONSVC.EXE
C:\WINDOWS\system32\r_server.exe
C:\Program Files\SlimServer\server\slim.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\AGRSMMSG.exe
C:\WINDOWS\system32\tp4serv.exe
C:\PROGRA~1\ThinkPad\UTILIT~1\TP98TRAY.EXE
C:\WINDOWS\system32\RunDll32.exe
C:\PROGRA~1\ThinkPad\CONNEC~1\Qctray.exe
C:\PROGRA~1\ThinkPad\PkgMgr\HOTKEY\TPHKMGR.exe
C:\WINDOWS\system32\dla\tfswctrl.exe
C:\WINDOWS\system32\AEIWLSTA.EXE
C:\Program Files\Java\jre1.5.0_06\bin\jusched.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgcc.exe
C:\PROGRA~1\Grisoft\AVGFRE~1\avgemc.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe
C:\Program Files\Winamp\winampa.exe
C:\Program Files\Picasa2\PicasaMediaDetector.exe
C:\Program Files\Messenger\msmsgs.exe
C:\Program Files\PeerGuardian2\pg2.exe
C:\Program Files\SlimServer\SlimTray.exe
C:\Program Files\Red Chair Software\Notmad Explorer\notmgr.exe
C:\Program Files\Google\Google Desktop Search\GoogleDesktopIndex.exe
C:\Program Files\X1\X1Systray.exe
C:\Program Files\X1\X1.exe
C:\Program Files\OpenOffice.org1.1.4\program\soffice.exe
C:\Program Files\Google\Google Desktop Search\GoogleDesktopDisplay.exe
C:\Program Files\Google\Google Desktop Search\GoogleDesktopCrawl.exe
C:\Program Files\iPod\bin\iPodService.exe
C:\Program Files\Google\Google Desktop Search\GoogleDesktopMail.exe
C:\Program Files\ThinkPad\PkgMgr\HOTKEY\TPONSCR.exe
C:\Program Files\ThinkPad\PkgMgr\HOTKEY_1\TpScrex.exe
C:\Program Files\Lavasoft\Ad-Aware SE Personal\Ad-Aware.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Program Files\Avant Browser\avant.exe
C:\WINDOWS\system32\ntvdm.exe
C:\Program Files\ewido anti-spyware 4.0\guard.exe
C:\Program Files\ewido anti-spyware 4.0\ewido.exe
C:\Program Files\Adobe\Acrobat 7.0\Reader\AcroRd32.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Adobe\Acrobat 7.0\Reader\AcroRd32Info.exe
C:\Hijackthis\HijackThis.exe

O2 - BHO: Yahoo! Companion BHO - {02478D38-C3F9-4efb-9B51-7695ECA05670} - C:\Program Files\Yahoo!\Companion\Installs\cpn\ycomp5_5_7_0.dll
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\Program Files\Spybot - Search & Destroy\SDHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.5.0_06\bin\ssv.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar2.dll
O3 - Toolbar: Yahoo! Companion - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\ycomp5_5_7_0.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar2.dll
O4 - HKLM\..\Run: [AGRSMMSG] AGRSMMSG.exe
O4 - HKLM\..\Run: [ATIModeChange] Ati2mdxx.exe
O4 - HKLM\..\Run: [TrackPointSrv] tp4serv.exe
O4 - HKLM\..\Run: [TPTRAY] C:\PROGRA~1\ThinkPad\UTILIT~1\TP98TRAY.EXE
O4 - HKLM\..\Run: [BMMGAG] RunDll32 C:\PROGRA~1\ThinkPad\UTILIT~1\pwrmonit.dll,StartPwrMonitor
O4 - HKLM\..\Run: [QCTRAY] C:\PROGRA~1\ThinkPad\CONNEC~1\Qctray.exe
O4 - HKLM\..\Run: [TP4EX] tp4ex.exe
O4 - HKLM\..\Run: [TPHOTKEY] C:\PROGRA~1\ThinkPad\PkgMgr\HOTKEY\TPHKMGR.exe
O4 - HKLM\..\Run: [StorageGuard] "C:\Program Files\VERITAS Software\Update Manager\sgtray.exe" /r
O4 - HKLM\..\Run: [dla] C:\WINDOWS\system32\dla\tfswctrl.exe
O4 - HKLM\..\Run: [AEIWLSTA.EXE] AEIWLSTA.EXE START
O4 - HKLM\..\Run: [SunJavaUpdateSched] C:\Program Files\Java\jre1.5.0_06\bin\jusched.exe
O4 - HKLM\..\Run: [AVG7_CC] C:\PROGRA~1\Grisoft\AVGFRE~1\avgcc.exe /STARTUP
O4 - HKLM\..\Run: [AVG7_EMC] C:\PROGRA~1\Grisoft\AVGFRE~1\avgemc.exe
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [Google Desktop Search] "C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe" /startup
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [WinampAgent] C:\Program Files\Winamp\winampa.exe
O4 - HKLM\..\Run: [Picasa Media Detector] C:\Program Files\Picasa2\PicasaMediaDetector.exe
O4 - HKLM\..\Run: [KernelFaultCheck] %systemroot%\system32\dumprep 0 -k
O4 - HKLM\..\Run: [!ewido] "C:\Program Files\ewido anti-spyware 4.0\ewido.exe" /minimized
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\msmsgs.exe" /background
O4 - HKCU\..\Run: [PeerGuardian] C:\Program Files\PeerGuardian2\pg2.exe
O4 - HKCU\..\Run: [updateMgr] C:\Program Files\Adobe\Acrobat 7.0\Reader\AdobeUpdateManager.exe AcRdB7_0_5 -reboot 1
O4 - Startup: Notmad Manager.lnk = C:\Program Files\Red Chair Software\Notmad Explorer\notmgr.exe
O4 - Startup: OpenOffice.org 1.1.4.lnk = C:\Program Files\OpenOffice.org1.1.4\program\quickstart.exe
O4 - Startup: X1 System Tray.lnk = C:\Program Files\X1\X1Systray.exe
O4 - Startup: X1.lnk = C:\Program Files\X1\X1.exe
O4 - Global Startup: Adobe Reader Speed Launch.lnk = C:\Program Files\Adobe\Acrobat 7.0\Reader\reader_sl.exe
O4 - Global Startup: Cisco Systems VPN Client.lnk = C:\Program Files\Cisco Systems\VPN Client\vpngui.exe
O4 - Global Startup: SlimServer Tray Tool.lnk = C:\Program Files\SlimServer\SlimTray.exe
O8 - Extra context menu item: &Google Search - res://c:\program files\google\GoogleToolbar2.dll/cmsearch.html
O8 - Extra context menu item: &Translate English Word - res://c:\program files\google\GoogleToolbar2.dll/cmwordtrans.html
O8 - Extra context menu item: Add to AD Black List - C:\Program Files\Avant Browser\AddToADBlackList.htm
O8 - Extra context menu item: Backward Links - res://c:\program files\google\GoogleToolbar2.dll/cmbacklinks.html
O8 - Extra context menu item: Block All Images from the Same Server - C:\Program Files\Avant Browser\AddAllToADBlackList.htm
O8 - Extra context menu item: Cached Snapshot of Page - res://c:\program files\google\GoogleToolbar2.dll/cmcache.html
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O8 - Extra context menu item: Highlight - C:\Program Files\Avant Browser\Highlight.htm
O8 - Extra context menu item: Open All Links in This Page... - C:\Program Files\Avant Browser\OpenAllLinks.htm
O8 - Extra context menu item: Open In New Avant Browser - C:\Program Files\Avant Browser\OpenInNewBrowser.htm
O8 - Extra context menu item: Search - C:\Program Files\Avant Browser\Search.htm
O8 - Extra context menu item: Similar Pages - res://c:\program files\google\GoogleToolbar2.dll/cmsimilar.html
O8 - Extra context menu item: Translate Page into English - res://c:\program files\google\GoogleToolbar2.dll/cmtrans.html
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_06\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_06\bin\ssv.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://update.microsoft.com/windowsupdate/v6/V5Controls/en/x86/client/wuweb_site.cab?1119657009934
O20 - Winlogon Notify: WgaLogon - C:\WINDOWS\SYSTEM32\WgaLogon.dll
O20 - Winlogon Notify: WRNotifier - C:\WINDOWS\SYSTEM32\WRLogonNTF.dll
O23 - Service: Ati HotKey Poller - Unknown owner - C:\WINDOWS\System32\Ati2evxx.exe
O23 - Service: AVG7 Alert Manager Server (Avg7Alrt) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVGFRE~1\avgamsvr.exe
O23 - Service: AVG7 Update Service (Avg7UpdSvc) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVGFRE~1\avgupsvc.exe
O23 - Service: Cisco Systems, Inc. VPN Service (CVPND) - Cisco Systems, Inc. - C:\Program Files\Cisco Systems\VPN Client\cvpnd.exe
O23 - Service: ewido anti-spyware 4.0 guard - Anti-Malware Development a.s. - C:\Program Files\ewido anti-spyware 4.0\guard.exe
O23 - Service: IBM PM Service (IBMPMSVC) - Unknown owner - C:\WINDOWS\system32\ibmpmsvc.exe
O23 - Service: iPod Service (iPodService) - Apple Computer, Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: QCONSVC - Unknown owner - C:\WINDOWS\System32\QCONSVC.EXE
O23 - Service: Remote Administrator Service (r_server) - Unknown owner - C:\WINDOWS\system32\r_server.exe" /service (file missing)
O23 - Service: SlimServer (slimsvc) - Unknown owner - C:\Program Files\SlimServer\server\slim.exe